To visit his grandmother, Christopher takes a scooter 2.88 kilometers and a horse 1.13 kilometers. In total, the journey takes 25.2 minutes. How many kilometers is Christopher's journey in total?
Answer: To find the total distance Christopher travels, we need to add the two distances together. Distance on scooter + distance on horse = total distance. ${2}$ ${8}$ ${8}$ ${1}$ ${1}$ ${3}$ ${+\vphantom{0}}$ ${1}$ ${0}$ ${4}$ Christopher travels 4.01 kilometers in total.